Core network node and method

ABSTRACT

The current disclosure proposes per UE customization of the UE DRX/eDRX and PSM based on the analytical results from NWDAF. It also proposes a new UE policy element for UE analytics reporting—UE Analytics Reporting Policy that is a set of reporting rules and is defined by the PCF based on analytical results from NWDAF. The UEARP then is delivered or updated in the UE during registration.

This application is a National Stage Entry of PCT/JP2019/048866 filed on Dec. 13, 2019, which claims priority from European Patent Application 19151050.2 filed on Jan. 9, 2019, the contents of all of which are incorporated herein by reference, in their entirety.

TECHNICAL FIELD

The present disclosure relates to a communication system. The disclosure has particular but not exclusive relevance to wireless communication systems and devices thereof operating according to the 3rd Generation Partnership Project (3GPP) standards or equivalents or derivatives thereof. The disclosure has particular although not exclusive relevance to customisation of UE mobility and connection management in the so-called ‘5G’ (or ‘Next Generation’) systems.

BACKGROUND ART Abbreviations 5GC 5G Core Network 5GS 5G System 5G-AN 5G Access Network 5G-S-TMSI 5G S-Temporary Mobile Subscription Identifier AMF Access and Mobility Management Function AN Access Network AS Access Stratum DN Data Network DRX Discontinuous Reception

eDRX extended Discontinuous Reception eNA enablers for Network Automation

GCF Global Certification Forum IMSI International Mobile Subscriber Identity MNG-RAN Master Next Generation Radio Access Network NAS Non-Access Stratum NEF Network Exposure Function NF Network Function NG-RAN Next Generation Radio Access Network NR New Radio NRF Network Repository Function NWDAF Network Data Analytics Function OAM Operation And Maintenance PCF Policy Control Function PDU Protocol Data Unit

PLMN Public land mobile network

PSM Power Saving Mode (R)AN (Radio) Access Network RAT Radio Access Technology RFSP RAT/Frequency Selection Priority RRC Radio Resource Control S-NSSAI Single Network Slice Selection Assistance Information SUCI Subscription Concealed Identifier SUPI Subscription Permanent Identifier UDM Unified Data Management UDR Unified Data Repository UE User Equipment UEARP UE Analytics Reporting Policy

VPLMN Visited Public land mobile network

Definitions

For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905 [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR 21.905 [1].

3GPP SA2 Working Group is working on eNA (enablers for Network Automation). The FIG. 1 from TR23.791 shows general framework for 5G network automation in Release 16, depicting that the NWDAF should be able to collect data from the operator OAM, AFs and 5GC network functions (NFs). Based on the data collection, the NWDAF performs data analysis and provides the analytical result to the AF, the 5GC NFs and the OAM.

As part of this study, exchange of information between NWDAF and OAM may be defined. Interactions between OAM and NWDAF shall be based on use case requirements. The OAM could be a potential consumer or provider of the information for the NWDAF. The definition of such interaction shall be coordinated with SA WG5.

For the collection of OAM data, the NWDAF shall reuse existing mechanisms and interfaces defined by SA WG5. For OAM information exchange beyond existing mechanisms and interfaces defined by SA WG5, close co-operation with SA WG5 is needed.

Depending on network deployments and on AF(s), the AF may exchange information with the NWDAF via the NEF, or use the service based interfaces to access the NWDAF directly.

NWDAF accesses network data from data repositories (e.g., UDR).

For 5GC NFs, the NWDAF utilizes the service based interfaces to communicate to get network data and dedicated analytics.

Based on the aforementioned data collection, the NWDAF performs data analysis and provides the analytical result to the AF, the 5GC NFs and the OAM.

The output of the analytics provided to the AF, NFs, and OAM by the NWDAF and vice versa will be defined depending on the selected solutions for the key issues.

PRIOR ART TR23.791, v1.1.0 5.2.9 Key Issue 9: Customizing Mobility Management Based on NWDAF Output 5.2.9.1 Description

As introduced in the investigated use case 4, diverse service scenarios in 5G will introduce different requirements on mobility support, which requires on demand mobility management in 5G network, i.e., the 5G network should apply customized mobility management for UEs with different mobility and/or different usage patterns.

In this key issue, it is supposed that the NWDAF can provide UE mobility related analytical report based on analysis on historical UE location, UE mobility behaviours and so on. Then, it will be feasible for the 5GC to use the NWDAF analytical results on a UE to customize the mobility management applied to the UE.

In order to support customizing mobility management based on NWDAF output, following issues are required to be investigated:

-   -   1) What analytical results can be provided by the NWDAF for per         UE mobility management optimization and what information is         provided to the NWDAF (i.e., what information from the relevant         5GS NF(s) and/or OAM and/or the other AF(s) is provided to the         NWDAF)?     -   NOTE: This key issue is to discuss and list the potential         information for the support of providing mobility related         analytical report while data collection framework and how NWDAF         collects the data is to be addressed by Key Issue 3:         Interactions with 5GS NFs/AFs for Data Collection and/or Key         Issue 4: Interactions with OAM for Data Collection and Data         Analytics Exposure Data Collection Framework.     -   2) Which network function(s) can directly interact with the         NWDAF to retrieve/receive the analytical results?     -   3) How to customize mobility management by NWDAF based outputs.         Examples of potential areas of investigation for customized         mobility management are: registration area allocation, paging         handling, mobility restriction area handling, NAS signaling         connection management, periodic registration timer handling,         handover decisions, overload avoidance, RFSP index change.

SUMMARY OF INVENTION Technical Problem

SA2 has studied the UE mobility customisation per UE under the Key Issue 9 during the Rel-16 eNA study (TR23.791 v2.0.0) agreeing solutions for UE registration area customisation based on analysis on historical UE location. However, the SA2 has also studied and agreed some solutions for optimizing connection management for the UE-NWDAF service operations should be enhanced to allow for providing statistics or predictions on communication patterns for the UE, as described in solution 22 (TR23.791 v2.0.0).

This proposal aims at further mobility and connection management optimizations for the UE based on the NWDAF analytics results.

Problem—What further analytical results can be provided by the NWDAF for per UE mobility and connection management optimisation. Then, how to customize the UE mobility and connection management by NWDAF based outputs. Examples of potential areas of investigation for customized mobility and connection are:

-   -   DRX/eDRX cycle lengths per UE customisation based on the         analytics results from the NWDAF i.e. how to decide for the best         DRX/.eDRX cycle length or PSM length per UE based on the         analytics results from the NWDAF for that UE to achieve best         power saving results. (problem 1);     -   back-off timers applicability and/or length per UE customisation         based on the analytics results from the NWDAF i.e. how to decide         whether to apply a back-off timer and if so with what length         based on the analytics results from the NWDAF for that UE to         avoid connection failures and allow for optimal load control.         (problem 2);     -   UE analytics reporting customisation per UE in time, location         and based on other considerations (problem 3).

Solution to Problem

According to an aspect of the present disclosure, a core network node includes: a controller configured to select a value for a back-off timer for mobility management for a user equipment (UE) based on a scheduled communication pattern of the UE.

According to another aspect of the present disclosure, a Network Data Analytic Function (NWDAF) node, includes: a transmitter configured to transmit, to a core network node, information for a scheduled communication pattern of a User Equipment (UE) for causing the core network node to select a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE.

According to another aspect of the present disclosure, a method for a core network node, includes: selecting a value for a back-off timer for mobility management for a user equipment (UE) based on a scheduled communication pattern of the UE.

According to another aspect of the present disclosure, a method for a Network Data Analytic Function (NWDAF) node, includes: transmitting, to a core network node, information for a scheduled communication pattern of a User Equipment (UE) for causing the core network node to select a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE.

Advantageous Effects of Invention

In certain aspects, a core network node, a NWDAF node, a method for a core network node, and a method for a NWDAF node may provide a technology for solving the problems as described above.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows general framework for 5G network automation.

FIG. 2 shows an example of NWDAF analytics for customized DRX/eDRX and PSM per UE.

FIG. 3 shows an example of NWDAF analytics for customized back-off timer per UE.

FIG. 4 shows an example of UE Analytics Report Policy (UEARP) build, delivery and update processing.

FIG. 5 schematically illustrates a mobile telecommunication system 1.

FIG. 6 is a block diagram illustrating, in more detail, the main components of the UE.

FIG. 7 is a block diagram illustrating, in more detail, the main components of an exemplary (R)AN node.

FIG. 8 is a block diagram illustrating, in more detail, the main components of a generic core network node.

DESCRIPTION OF EMBODIMENTS

Aspect 1—NWDAF Analytics for UE Mobility and Connection Management Customization.

Example 1: NWDAF Analytics for Customised DRX/eDRX and PSM Per UE

The Example 1 addresses the Problem 1, i.e., how to use the analytical output from the NWDAF 720 in order to customise the connection management per UE (e.g., DRX/eDRX and PSM per UE), see FIG. 2:

1-2) The AMF 710 subscribes for analytical results information from the NWDAF 720. The UE 3 may indicate the type of analytical information it is subscribing to, e.g., DRX/eDRX cycle and/or PSM analytics per UE. For example, these procedures may be invoked by a Nnwdaf_EventsSubscription_Subscribe Request procedure and a Nnwdaf_EventsSubscription_Subscribe Response procedure.

3) When the UE 3 registers with the network, the UE 3 requests DRX/eDRX. For example, this procedure may be invoked by a UE Registration Request procedure.

4) The AMF 710 may enquire with the UDM/UDR 730 for UE subscription information including subscription information related to the DRX/eDRX, the RAT being used and the PSM for this UE 3. For example, this procedure may be invoked by a Nudm_SDM_Get procedure.

5) The AMF 710 also requests analytical information from the NWDAF 720 for that UE 3 related to the DRX/eDRX and/or the RAT being used and/or the PSM. For example, this procedure may be invoked by a Nnwdaf_AnalyticsInfo_Request procedure where the AMF 710 includes the following parameters in the Nnwdaf_AnalyticsInfo_Request message:

-   -   UE_Id—UE identity for which analytics information is required         from the NWDAF 720. The UE_Id may be represented by the UE's         5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of the UE         identity representation.     -   DRX/eDRX/PSM—this is to identify the type of the required         analytics information from the NWDAF 720 related to the UE 3         whose UE_Id is included in the Nnwdf_AnalyticsInfo_Request         message.

6) The NWDAF 720 collects statistical information for the UEs 3 from different sources e.g., directly from the UE 3, from other Network Functions (NFs), from the OAM and from the Service provider (AFs) via the network exposure, directly or via the NEF. When the NWDAF 720 is requested for analytical information by the AMF 710 related to the connection management (e.g., a customised per UE DRX/eDRX and/or RAT being used and/or PSM information), the NWDAF 720 analyses all the collected statistic and analytics information available for that UE 3 related to connection management, e.g., the frequency of mobile terminated (MT) calls, the frequency of mobile originated (MO) calls, is it a scheduled communications (e.g., the days and the time of the days the communication takes place), whether the UE 3 is battery powered UE and if so what the current level of the UE battery is, what type of S-NSSAIs the PDU connections are requested for (e.g., low priority applications, or delay tolerant applications) and etc.

Based on these inputs, the NWDAF 720 works out a proposal for the best DRX/eDRX cycle (e.g., longer DRX/eDRX cycle for the UEs 3 with requirement for power save and the UEs 3 with predominantly mobile originated traffic and for the UEs 3 that store delay tolerant applications) and the PSM length for that UE 3 (e.g., longer PSM interval for UEs 3 with communication pattern that suggest a rare communication or communication at specific times or for the UEs 3 with predominantly MO type of communication).

7) The NWDAF 720 provides the AMF 710 with a proposed DRX/eDRX cycle, RAN type and/or PSM interval. For example, this process may be invoked by a Nnwdaf_AnalyticInfo_Response procedure where the NWDAF 720 includes the following parameters in the Nnwdaf_AnalyticsInfo_Response message:

-   -   UE_Id—UE identity for which the analytics information is         provided by the NWDAF 720. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         UE identity representation.     -   DRX/eDRX/PSM—this is to identify the type of the analytics         information provided by the NWDAF 720 related to the UE 3 whose         UE_Id is included in the Nnwdf_AnalyticsInfo_Response message.

8) The AMF 710 considers the DRX/eDRX requested by the UE 3 and the DRX/eDRX, RAN type and PSM length proposed by the NWDAF 720 (or the analytical results related to the DRX/eDRX and/or PSM for that UE 3), the UE subscription information related to the DRX/eDRX and PSM, the UE policy rules and operator configuration (if any), and based on all these and other inputs, the AMF 710 works out the DRX/eDRX and/or PSM customised for that UE 3. This way the AMF 710 is able to assign to the UE 3 a customised DRX/eDRX and/or PSM that are best suited for the UE 3 in terms of connection management, leading to:

-   -   UE power saving (e.g., due to assigning longer DRX/eDRX cycle         and PSM interval to the UEs 3 with predominantly MO type of         traffic and/or scheduled communication and/or with communication         of delay tolerant type);     -   Reduced call delays (e.g., due to assigning shorter DRX/eDRX         cycle and PSM interval to the UEs 3 with frequent type of         communication pattern and/or with communication of predominantly         MT type of calls);     -   Reduced data buffering in downlink (e.g., due to assigning         shorter DRX/eDRX cycle and PSM interval to the UEs 3 with         communication of predominantly MT type of calls and or with time         sensitive communication).

9) The AMF 710 returns the per UE customised DRX/eDRX and/or PSM to the UE 3 with the Registration Accept message.

The ‘per UE’ customised DRX/eDRX cycle length and PSM length allow for:

-   -   UE power saving—if the analytic results from the NWDAF 720         reveal that the UE 3 is with predominantly MO type of traffic or         with scheduled type of communication or the communication is of         delay tolerant type, the AMF 710 may assign longer DRX/eDRX         cycle or PSM length to the UE 3 with consideration of the         schedule of communication (if scheduled type communication) so         that the UE 3 can achieve best power saving results.     -   Reduced call delays—if the analytic results from the NWDAF 720         reveal that the UE 3 is with frequent type of communication         pattern and/or with communication of predominantly MT type of         calls, the AMF 710 may assign shorter DRX/eDRX cycle or PSM         length to the UE 3 to reduce to minimum the delays in paging         that UE 3.     -   Reduced downlink data buffering—if the analytic results from the         NWDAF 720 reveal that the UE 3 is with communication of         predominantly MT type of calls and or with time sensitive         communication, the AMF 710 may assign a shorter DRX/eDRX cycle         or PSM length to the UE 3 which would lead to reduced data         buffering in downlink.

Example 2: NWDAF Analytics for Customised Back-Off Timers Per UE

The Example 2 addresses problem 2, i.e. how to use the analytical output from the NWDAF 720 in order to customise the connection management per UE (e.g., the overload control via customised back-off timers per UE). This aspect includes the following steps, see FIG. 3.

1-2) The AMF 710 subscribes for analytical results information from the NWDAF 720. The UE 3 may indicate the type of analytical information it is subscribing to, e.g., back-off timer analytics. For example, these procedures may be invoked by a Nnwdaf_EventsSubscription_Subscribe Request procedure and a Nnwdaf_EventsSubscription_Subscribe Response procedure.

3) The UE 3 registers with the network. For example, this procedure may be invoked by a UE Registration Request procedure.

4) The AMF 710 may enquire with the UDM/UDR 730 for UE subscription information including subscription information related to back-off timers for this UE 3. For example, this procedure may be invoked by a Nudm_SDM_Get procedure.

5) The AMF 710 requests analytical information from the NWDAF 720 related to the back-off timer to be used with that UE 3. For example, this procedure may be invoked by a Nnwdaf_AnalyticsInfo_Request procedure where the AMF 710 includes the following parameters in the Nnwdaf_AnalyticsInfo_Request message:

-   -   UE_Id—UE identity for which the analytics information is         required from the NWDAF 720. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   back-off timer analytics—this is to identify the type of the         required analytics information from the NWDAF 720 related to the         UE 3 whose UE_Id is included in the Nnwdf_AnalyticsInfo_Request         message.

6) The NWDAF 720 collects statistical information for UEs from different sources e.g., directly from the UE 3, from other Network Functions (NFs), from the OAM and from the Service provider (AFs) via the network exposure, directly or via the NEF. When the NWDAF 720 is requested for analytical information by the AMF 710 related to the connection management (e.g., a customised per UE back-off timer), the NWDAF 720 analyses all the collected statistic and analytics information available for that UE 3 related to connection management, e.g., scheduled communications (e.g., the days and the time of the days the communication takes place), the length of the communication, whether the UE 3 is a battery powered UE, and etc.

Based on these inputs, the NWDAF 720 may work out a proposal indicating:

-   -   whether it is appropriate for the network to apply a back-off         timer for that UE 3 when the network is overloaded (e.g., if the         analytical result from the NWDAF 720 reveals that the UE 3 does         scheduled communication only, the NWDAF 720 may suggest the AMF         710 not to apply a back-off timer as the UE 3 would miss its         communication time slot. Also, the UE 3 is battery powered and         the battery level of the UE 3 is running low, the NWDAF         analytical result may again suggest that this UE 3 is not         applied a back-off timer.)

7) The NWDAF 720 provides the AMF 710 with an analytical result related to the back-off timer use and possibly the length of the back-off timer. For example, this process may be invoked by a Nnwdaf_AnalyticInfo_Response procedure where the NWDAF 720 includes the following parameters in the Nnwdaf_AnalyticsInfo_Response message:

-   -   UE_Id—UE identity for which the analytics information is         provided by the NWDAF 720. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   back-off timer analytics—this is to identify the type of the         analytics information provided by the NWDAF 720 related to the         UE 3 whose UE_Id is included in the Nnwdf_AnalyticsInfo_Response         message.

8) The AMF 710 considers the back-off timer related proposal from the NWDAF 720 (or the analytical results related to the applicability of the back-off timer and possibly the length of the back-off timer) for that UE 3, the UE subscription information, and the UE policy rules configuration, and based on all these and other inputs, the AMF 710 may decide on:

-   -   whether it is appropriate for the network to apply a back-off         timer for that UE 3 when the network is overloaded, e.g., if the         analytical result from the NWDAF 720 reveals that the UE 3 does         scheduled communication only, the NWDAF 720 may suggest the AMF         710 not to apply a back-off timer as the UE 3 would miss its         communication time slot in case the back-off timer would expire         out of the UE allowed communication slot/window. Alternatively,         the AMF 710 may apply a shorter back-off timer so that the UE 3         can retry before the end of its allowed communication window.         Also, if the UE 3 is battery powered and the battery level of         the UE 3 is running low, the NWDAF analytical results from the         NWDAF 720 may again suggest that this UE 3 is not applied a         back-off timer.     -   what length of the back-off timer to apply, e.g., the NWDAF 720         may propose a length for the back off timer based on the         analytical results that the communication from that UE 3 is         scheduled communication and considering the timeslot for         communication.

9) The AMF 710 returns to the UE 3 the Registration Accept message.

The back-off timer is assigned to the UE 3 with one of the NAS messages, e.g., Registration Accept message, Service Accept message, Service Reject message or any other NAS message.

Aspect 2—UE Analytics Report Policy (UEARP) Build Up, Delivery and Update.

The Aspect 2 addresses problem 3. It is about configuration and management of the UE Analytics reporting. The Aspect 2 defines a UE Analytics Report Policy element (e.g., data structure with various rules for the UE Analytics reporting) that is built up by the PCF 740 based on analytics information from the NWDAF 720, subscription information and operators configuration policies, if any. Then, the UEARP is configured in the UE 3 during the UE registration procedure or via a UE Configuration update procedure. The UEARP is a set of UE analytics report policies which defines the rules for the UE analytics reporting, like what kind of analytics to be reported by the UE 3, when to report (e.g., triggers for reporting like entering defined locations, meeting defined requirements, time triggers and more). The Aspect 2 includes the following steps, see FIG. 4.

1-2) The PCF 740 subscribes for analytical results information from the NWDAF 720. The PCF 740 may use a UEARP parameter to set up the types of analytics it is subscribing to. For example, these procedures may be invoked by a Nnwdaf_EventsSubscription_Subscribe Request procedure and a Nnwdaf_EventsSubscription_Subscribe Response procedure.

3) The UE 3 triggers registration with the network. The UE 3 may include in the registration request message its current UEARP. For example, this procedure may be invoked by a UE Registration Request procedure.

4) The AMF 710 may enquire with the PCF 740 to check for any UEARP update. Alternatively, the AMF 710 may have been notified by the PCF 740 with the updated version of the UEARP for that UE 3. For example, this procedure may be invoked by a Npcf_AM Policy Update Notify procedure where the AMF 710 includes the following parameters in the Npcf_AM Policy Update Notify message:

-   -   UE_Id—UE identity for which checks for UEARP rules updates are         required in the PCF 740. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   UEARP—this is to identify the type of information required from         the PCF 740. The UEARP may also contain the current UEARP rules         reported by the UE 3 against which the PCF 740 shall check for         any updates to the current UEARP rules for the UE 3 for which         the UE_Id is included in the Npcf_AM Policy Update Notify         message.

5) The PCF 740 requests analytical information from the NWDAF 720 for that UE 3 related to the UEARP. For example, this procedure may be invoked by a Nnwdaf_AnalyticsInfo_Request procedure where the PCF 740 includes the following parameters in the Nnwdaf_AnalyticsInfo_Request message:

-   -   UE_Id—UE identity for which the analytics information is         required from the NWDAF 720. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   UEARP—this is to identify the type of the required analytics         information from the NWDAF 720 related to the UE 3 whose UE_Id         is included in the Nnwdf_AnalyticsInfo_Request message.

6) Based on the analytical data collection and analysis by the NWDAF 720 for that UE 3, the NWDAF 720 works out a proposal for the UEARP for that UE 3.

7) The NWDAF 720 provides the PCF 740 with the UEARP analytics or with a proposal for the UEARP. For example, this process may be invoked by a Nnwdaf_AnalyticInfo_Response procedure where the NWDAF 720 includes the following parameters in the Nnwdaf_AnalyticsInfo_Response message:

-   -   UE_Id—UE identity for which the analytics information is         provided by the NWDAF 720. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   UEARP—this is to identify the type of the analytics information         provided from the NWDAF 720 related to the UE 3 whose UE_Id is         included in the Nnwdf_AnalyticsInfo_Response message.

8) The PCF 740 updates the UE's UEARP based on the NWDAF proposed analytics result about the UEARP (or an UEARP proposal), UE subscription information and any available relevant operator policies. The PCF 740 may inform the proposed updates by the NWDAF 720 to the AF and/or the UDM 730 in order to synchronize data in each nodes. If the proposed updates by the NWDAF 720 is not acceptable by the AF and/or the UDM 730, the AF and/or the UDM 730 indicates it to the PCF 740. In this case, the PCF 740 does not update the UE's UEARP.

9) The PCF 740 may respond to the AMF 710 by sending the updated (if any) UEARP. For example, this procedure may be invoked by a Npcf_AM Policy Update Notify procedure where the PCF 740 includes the following parameters in the Npcf_AM Policy Update Notify message:

-   -   UE_Id—UE identity for which UEARP rules (new or updated) are         provided from the PCF 740. The UE_Id may be represented by the         UE's 5G-S-TMSI or SUPI or IMSI or SUCI or by any other form of         the UE identity representation.     -   UEARP—the UEARP rules (new or updated) provided from the PCF 740         for the UE 3 for which the UE_Id is included in the Npcf_AM         Policy Update Notify message.

10) The AMF 710 delivers the updated (if any) UEARP to the UE 3 with the Registration Accept message. The updated UEARP may also be delivered to the UE 3 via the UE Configuration Update message.

In another implementation, the UEARP rules can also be delivered as part of the UE Policy during the Registration procedure or via the UE Configuration Update message.

The UE configuration and update with the UEARP rules allows for the network (e.g., operator or service provider) to control and manage the UE analytics reporting from the UE 3, like what type of analytics to be reported by the UE 3, when to report (e.g., triggers for reporting like entering defined locations, meeting defined requirements, time triggers and more). This allows for reporting only of UE analytics that is required and reporting at the time they are required which leads to savings in the UE power, saving in the UE 3 and network resources and reduced signalling between the UE 3 and the network.

Some exemplary UE Analytics Report Policy (UEARP) rules are shown in Table 1.

TABLE 1 UEARP rules UEARP rule ID UEARP event filter Description Location Cell, list of Cells, The PCF request the UE to start UE triggered TA, list of TAs, analytics reporting when the UE reporting Registration Area enters a location defined by the UEARP event filter. Time Defined times per The PCF requests the UE to start UE triggered day/week/month, analytics reporting at specific times reporting Length of reporting of the day or week or month set by timeslot the UEARP event filter. The PCF may also define the length of reporting time. Event Designated message The PCF triggers the UE to start UE triggered or parameter analytics reporting by sending a reporting received by the designated message or a designated network parameter in an existing message. Scheduled Defined timeslot per The PCF requests the UE to start UE reporting day/week/month, analytics reporting at specific time- Length of reporting slots of the day or week or month set timeslot by the UEARP event filter. The PCF may also define the length of reporting time. Reporting The type of the The PCF requests the UE to start UE data set reported analytics analytics reporting for a set of UE data (e.g. UE location, analytics data defined by the UEARP UE mobility, UE filter. serving cell signal strength, UE out of service entries, UE call drops and etc)

Summary

Beneficially, the above described aspects include, although they are not limited to, one or more of the following functionalities:

Aspect 1:

1) The AMF 710 subscribes for and gets analytics results from the NWDAF node 720 in order to improve and optimise the mobility and connection management of the UE 3 by providing the UE 3 with:

-   -   Per UE customised DRX/eDRX and PSM.     -   Per UE customised back-off timer.

Aspect 2:

2) Defines a UE Analytics Report Policy (UEARP) element as a set of UE analytics reporting policies which defines the rules for the UE analytics reporting, like what kind of analytics to be reported by the UE 3, when to report (e.g., triggers for UE analytics reporting like location triggered reporting, time triggered reporting, event triggered and more.

In order to provide these functionalities, the above aspects describe exemplary methods comprising (at least some of) the following steps:

Aspect 1:

Example 1

1) AMF subscription for DRX/eDRX and PSM related NWDAF analytics results

2) DRX/eDRX cycle and PSM customisation per UE based on the analytical results from the NWDAF 720 and the UDM/UDR 730.

Example 2

1) AMF subscription for back-off timer related NWDAF analytics results

2) Back-off timer customisation per UE based on the analytical results from the NWDAF 720 and the UDM/UDR 730.

Aspect 2:

1) PCF subscription with the NWDAF 720 for UE Analytics Report Policy (UEARP) related analytical results.

2) The PCF 740 defines UEARP per UE.

3) UEARP delivery to UE 3 in the registration procedure or via the UE Configuration Update procedure.

Benefits

This document proposes how the AMF 710 and the PCF 740 can use the analytics result from the NWDAF 720 to improve the UE mobility and connection management by working out customised per UE DRX/eDRX, PSM, back-off timer and UE Analytical Report Policy.

System Overview

FIG. 5 schematically illustrates a mobile (cellular or wireless) telecommunication system 1 to which the above aspects and examples are applicable.

In this network, users of mobile devices 3 (UEs) can communicate with each other and other users via respective base stations 5 and a core network 7 using an appropriate 3GPP radio access technology (RAT), for example, an E-UTRA and/or 5G RAT. It will be appreciated that a number of base stations 5 form a (radio) access network or (R)AN. As those skilled in the art will appreciate, whilst one mobile device 3 and one base station 5 are shown in FIG. 5 for illustration purposes, the system, when implemented, will typically include other base stations and mobile devices (UEs).

Each base station 5 controls one or more associated cells (either directly or via other nodes such as home base stations, relays, remote radio heads, distributed units, and/or the like). The base station 5 that supports E-UTRA (Evolved Universal Terrestrial Radio Access)/4G protocols may be referred to as an ‘eNB’ (evolved NodeB) and a base station 5 that supports NextGeneration/5G protocols may be referred to as a ‘gNBs’ (next generation NodeBs). It will be appreciated that some base stations 5 may be configured to support both 4G and 5G, and/or any other 3GPP or non-3GPP communication protocols.

The mobile device 3 and its serving base station 5 are connected via an appropriate air interface (for example the so-called ‘Uu’ interface and/or the like). Neighbouring base stations 5 are connected to each other via an appropriate base station to base station interface (such as the so-called ‘X2’ interface, ‘Xn’ interface and/or the like). The base station 5 is also connected to the core network nodes 10, 11 via an appropriate interface (such as the so-called ‘S1’, ‘N1’, ‘N2’, ‘N3’ interface, and/or the like).

The core network 7 typically includes logical nodes (or ‘functions’) for supporting communication in the telecommunication system 1. Typically, for example, the core network 7 of a ‘Next Generation’/5G system will include, amongst other functions, control plane functions (CPFs) 10 and user plane functions (UPFs) 11. Such control plane functions 10 (and user plane functions 11) may provide the functionality of the AMF 710, the NWDAF 720, the UDM/UDR 730, the PCF 740, and/or the OAM discussed in the above aspects.

From the core network 7, connection to an external IP network 20 (such as the Internet) is also provided.

The components of this system 1 are configured to perform the above described aspects.

User Equipment (UE)

FIG. 6 is a block diagram illustrating, in more detail, the main components of the UE (mobile device 3) shown in FIG. 5. As shown, the UE 3 includes a transceiver circuit 31 which is operable to transmit signals to and to receive signals from the connected node(s) via one or more antenna 33. Although not necessarily shown, the UE will of course have all the usual functionality of a conventional mobile device (such as a user interface 35) and this may be provided by any one or any combination of hardware, software and firmware, as appropriate. A controller 37 controls the operation of the UE in accordance with software stored in a memory 39. The software may be pre-installed in the memory 39 and/or may be downloaded via the telecommunication network 1 or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 41 and a communications control module 43. The communications control module 43 is responsible for handling (generating/sending/receiving) signalling messages, including uplink/downlink data packets, between the UE 3 and other nodes (e.g., (R)AN nodes 5 and core network nodes 10, 11), in accordance with any one of the above described aspects.

(R)AN Node

FIG. 7 is a block diagram illustrating, in more detail, the main components of an exemplary (R)AN node 5 (base station 5) shown in FIG. 5. As shown, the (R)AN node 5 includes a transceiver circuit 51 which is operable to transmit signals to and to receive signals from connected UE(s) 3 via one or more antenna 53 and to transmit signals to and to receive signals from other network nodes (either directly or indirectly) via a network interface 55. The network interface 55 typically includes an appropriate base station—base station interface (such as X2/Xn) and an appropriate base station—core network interface (such as S1/N1/N2/N3). A controller 57 controls the operation of the (R)AN node 5 in accordance with software stored in a memory 59. The software may be pre-installed in the memory 59 and/or may be downloaded via the telecommunication network 1 or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 61 and a communications control module 63. The communications control module 63 is responsible for handling (generating/sending/receiving) signalling between the (R)AN node 5 and other nodes, such as the UE 3 and the core network nodes 10, 11/network elements. Such signalling includes appropriately formatted messages (and information elements thereof) in accordance with any one of the above described aspects.

Core Network Node

FIG. 8 is a block diagram illustrating, in more detail, the main components of a generic core network node 10, 11 (network element or function) shown in FIG. 5. It will be appreciated that this block diagram may also apply to network nodes outside the core network 7, e.g., the OAM. As shown, the core network node 10, 11 includes a transceiver circuit 71 which is operable to transmit signals to and to receive signals from other nodes (including the UE 3 and the (R)AN node 5) via a network interface 75. A controller 77 controls the operation of the core network node 10, 11 in accordance with software stored in a memory 79. The software may be pre-installed in the memory 79 and/or may be downloaded via the telecommunication network 1 or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 81 and at least a communications control module 83. The communications control module 83 is responsible for handling (generating/sending/receiving) signaling between the core network node 10, 11 and other nodes, such as the UE 3, (R)AN node 5, and other core network nodes 10, 11. Such signaling includes appropriately formatted messages in accordance with any one of the above described aspects.

MODIFICATIONS AND ALTERNATIVES

Detailed aspects have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above aspects whilst still benefiting from the disclosures embodied therein. By way of illustration only a number of these alternatives and modifications will now be described.

In the above description, the UE, the (R)AN node, and the core network node are described for ease of understanding as having a number of discrete modules (such as the communication control modules). Whilst these modules may be provided in this way for certain applications, for example where an existing system has been modified to implement the disclosure, in other applications, for example in systems designed with the inventive features in mind from the outset, these modules may be built into the overall operating system or code and so these modules may not be discernible as discrete entities. These modules may also be implemented in software, hardware, firmware or a mix of these.

Each controller may comprise any suitable form of processing circuitry including (but not limited to), for example: one or more hardware implemented computer processors; microprocessors; central processing units (CPUs); arithmetic logic units (ALUs); input/output (TO) circuits; internal memories/caches (program and/or data); processing registers; communication buses (e.g., control, data and/or address buses); direct memory access (DMA) functions; hardware or software implemented counters, pointers and/or timers; and/or the like.

In the above aspects, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the UE, the (R)AN node, and the core network node as a signal over a computer network, or on a recording medium. Further, the functionality performed by part or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of the UE, the (R)AN node, and the core network node in order to update their functionalities.

The above aspects are also applicable to ‘non-mobile’ or generally stationary user equipment.

Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

CITATION LIST Non Patent Literature

-   [NPL 1] 3GPP TR 21.905: “Vocabulary for 3GPP Specifications” V15.0.0     (March 2018) -   [NPL 2] 3GPP TS 23.501: “System Architecture for the 5G System;     Stage 2” V15.3.0 (September     2018)—http://www.3gpp.org/ftp/Specs/archive/23     series/23.501/23501430.zip -   [NPL 3] 3GPP TS 23.502: “Procedures for the 5G System; Stage 2”     V15.3.0 (September 2018)—http://www.3gpp.org/ftp/Specs/archive/23     series/23.502/23502-f30.zip -   [NPL 4] 3GPP TR23.791 “Study of Enablers for Network Automation for     5G” V2.0.0 (December     2018)—http://http://www.3gpp.org/ftp/Specs/archive/23     series/23.791/23791-200.zip

This application is based upon and claims the benefit of priority from European patent application No. 19151050.2, filed on Jan. 9, 2019, the disclosure of which is incorporated herein in its entirely by reference.

REFERENCE SIGNS LIST

-   1 telecommunication system -   3 UE -   31 transceiver circuit -   33 antenna -   35 user interface -   37 controller -   39 memory -   41 operating system -   43 communications control module -   5 (R)AN node -   51 transceiver circuit -   53 antenna -   55 network interface -   57 controller -   59 memory -   61 operating system -   63 communications control module -   7 core network -   71 transceiver circuit -   75 network interface -   77 controller -   79 memory -   81 operating system -   83 communications control module -   710 AMF -   720 NWDAF -   730 UDM/UDR -   740 PCF -   10 CPF -   11 UPF -   20 external IP network 

What is claimed is:
 1. A core network node comprising: a memory storing instructions; and at least one processor configured to process the instructions to: receive information for determining a scheduled communication pattern of user equipment (UE) from a Network Data Analytic Function (NWDAF) node; and select a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE, wherein the information for determining the scheduled communication pattern of the UE is an analytic result by the NWDAF node based on information on scheduled communications for the UE, and the scheduled communication pattern of the UE indicates a scheduled communication window in which the UE is available for communication.
 2. The core network node according to claim 1, wherein the at least one processor is further configured to process the instructions to: select the value so that the UE does not miss the scheduled communication window.
 3. The core network node according to claim 2, wherein the at least one processor is further configured to process the instructions to: select the value which is shorter than the scheduled communication window.
 4. The core network node according to claim 2, wherein the at least one processor is further configured to process the instructions to: apply no back-off timer based on the scheduled communication window.
 5. (canceled)
 6. The core network node according to claim 1, wherein the information for determining the scheduled communication pattern of the UE indicates that the UE communicates based on the scheduled communication pattern of the UE.
 7. A Network Data Analytic Function (NWDAF) node, comprising: a memory storing instructions; and at least one processor configured to process the instructions to: transmit, to a core network node, information for determining a scheduled communication pattern of User Equipment (UE) for causing the core network node to select a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE, wherein the information for determining the scheduled communication pattern of the UE is an analytic result by the NWDAF node based on information on scheduled communications for the UE, and the scheduled communication pattern of the UE indicates a scheduled communication window in which the UE is available for communication.
 8. A method for a core network node, comprising: receiving information for determining a scheduled communication pattern of user equipment (UE) from a Network Data Analytic Function (NWDAF) node; and selecting a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE, wherein the information for determining the scheduled communication pattern of the UE is an analytic result by the NWDAF node based on information on scheduled communications for the UE, and the scheduled communication pattern of the UE indicates a scheduled communication window in which the UE is available for communication.
 9. The method according to claim 8, wherein the selecting includes selecting the value so that the UE does not miss the scheduled communication window.
 10. The method according to claim 9, wherein the selecting includes selecting the value which is shorter than the scheduled communication window.
 11. The method according to claim 9, wherein the selecting is performed by applying no back-off timer based on the scheduled communication window.
 12. A method for a Network Data Analytic Function (NWDAF) node, comprising: transmitting, to a core network node, information for determining a scheduled communication pattern of User Equipment (UE) for causing the core network node to select a value for a back-off timer for mobility management for the UE based on the scheduled communication pattern of the UE, wherein the information for determining the scheduled communication pattern of the UE is an analytic result by the NWDAF node based on information on scheduled communications for the UE, and the scheduled communication pattern of the UE indicates a scheduled communication window in which the UE is available for communication. 